(a) Field of the Invention
The present invention relates to an artificial magnetic conductor. More particularly, the present invention relates to an artificial magnetic conductor having a modified ground layer.
(b) Description of the Related Art
An artificial magnetic conductor is a metamaterial representing a phenomenon that does not generally exist in nature, and has been in the spotlight as core technology that can overcome a physical limitation of existing technology. Such an artificial magnetic conductor has a structure of a surface artificially having characteristics of a magnetic conductor in a specific frequency domain, unlike an electric conductor that can be seen naturally.
The artificial magnetic conductor is formed with an electric conductor. A surface of the artificial magnetic conductor is formed in a protrusion structure to generate a capacitance component and an inductance component. These components can be represented with a frequency function, and surface impedance significantly increases by the components in a specific frequency domain. In a general conductor, surface impedance has a value of “0” and a reflection coefficient has a value of “−1” and thus an image current has an inverse phase, but in an artificial magnetic conductor, surface impedance has a very large value and a reflection coefficient has a value of “+1” and thus an image current has the same phase. Further, propagation of a surface wave can be suppressed due to high surface impedance.
Such a conventional artificial magnetic conductor has a general conductor plate that is not modified as a ground layer. In a conventional artificial magnetic conductor that has a general conductor plate as a ground layer and that is formed in the same grid cell size, in order to lower a frequency domain, a method of increasing capacitance between grid cells or increasing inductance is used. However, when increasing capacitance using grid cells, a frequency bandwidth operating as an artificial magnetic conductor becomes narrow, and when increasing inductance, the size and weight of the artificial magnetic conductor structure increase.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.